Fireworks are prohibited within the City of Sioux Center, except during the dates allowed: June 13-July 8 between 9 a.m.-10 p.m., with extended use to 11 p.m. on July 4 and the Saturdays/Sundays before and after July 4 (up to July 8). Must be 18 to use. A $250 fine applies for misuse.